In college, women’s hockey players are reporting concussions at a higher rate than male hockey players. In fact, female hockey players are reporting a higher concussion rate than nearly all sports sanctioned by the National Collegiate Athletic Association (NCAA). In several studies, female hockey players have reported concussions more often than men’s college football, and at a rate that is comparable to men’s college wrestling and men’s college ice hockey.

Compared to sports like women’s tennis or women’s basketball, hockey is faster, played on harder surfaces, and involves more collisions, which partly explains the high rate of concussions but doesn’t account for the fact that female athletes are reporting more concussions than male athletes who also play hockey. In fact, several surveys have demonstrated that, besides hockey, female athletes consistently report a higher concussion rate than male athletes playing the same gender comparable sport (e.g basketball, soccer, softball/baseball).

The reasons why are unclear, but this video highlights some of the plausible factors, including: gender bias, reporting bias, differences in style of play (for example, body checking is allowed in men’s hockey and is illegal in women’s hockey), hormonal differences (progesterone is of particular interest to researchers), neck strength, and differences in the structure of nerve fibers called axons.

To help understand how these factors might influence the concussion rates, this video features interviews with University of North Carolina researcher Zachary Kerr and retired US Women’s Hockey player Josephine Pucci, who ended her career following several concussions. To hear her story of how she came back to win a 2014 Olympic Silver Medal while playing on the Harvard Women’s team, make sure to watch the video above.